1. Field of the Invention
The present invention relates to a method and system for starting an automotive internal combustion engine. More particularly, the present invention relates to a method and system for starting an automotive engine designed to diminish load torque as the engine is started.
2. Related Art
Japanese Unexamined Patent Publication No. 3-3969 discloses improving the starting ability of an internal combustion engine by applying normal rotational torque for a constant time after receipt of a starting command or start of engine cranking. When a failure has occurred in starting the engine due to heat lock or the like, forward and reverse rotation of the starter is performed alternately in response to a starting command.
In such a system, after application of normal forward rotational torque, the system determines whether rotation stops after a given time. In this case, the system decides a starting failure only after the given time. Then, the system enters the reverse mode. This system creates the problem that considerable time is necessitated until the starting failure is detected. Therefore, even if the engine starting is successfully made by the reverse rotation after the failure in the first forward rotation, many operators are dissatisfied with the difficulty involved in starting the engine using such a system.
In the above prior art, the normal or forward rotation is performed first in each starting irrespective of direction of changes in the load torque which the starter should overcome at the very start of rotation. If the system carries out forward rotation at first and this is in the same direction as the load torque increase, the engine hardly rotates and may stop entirely. This is a waste of both time and effort, not to mention of electrical power.